Improve matching algorithm documentation

README.md

@@ -200,8 +200,11 @@ this in several stages:
   looks at the asset filenames to see which ones match your OS, using a (hopefully complete) regex.
 - Next it filters based on your CPU architecture, which is something like x86-64, ARM64, PowerPC,
   etc. Again, this is done with a regex.
-- If you are running on a Linux system using musl as its libc, it will also filter based on this to
-  filter out anything _not_ compiled against musl.
+- If you are running on a Linux system using musl as its libc, it will also filter out anything
+  _not_ compiled against musl. This filter looks to see if the file name contains an indication of
+  which libc it was compiled against. Typically, this is something like "-gnu" or "-musl". If it
+  does contain this indicator, names that are _not_ musl are filtered out. However, if there is no
+  libc indicator, the asset will still be included.
 
 At this point, any remaining assets should work on your platform. If there's more than one at this
 point, it attempts to pick the best one.

ubi/src/lib.rs

@@ -87,17 +87,22 @@
 //!   complete) regex.
 //! - Next it filters based on your CPU architecture, which is something like x86-64, ARM64, PowerPC,
 //!   etc. Again, this is done with a regex.
-//! - If you are running on a Linux system using musl as its libc, it will also filter based on this
-//!   to filter out anything _not_ compiled against musl. You can set this explicitly with the
-//!   [`UbiBuilder::is_musl`] function. If this wasn't set, then it will try to detect if you are
-//!   using musl by looking at the output of `ldd /bin/ls`.
+//! - If you are running on a Linux system using musl as its libc, it will also filter out anything
+//!   _not_ compiled against musl. This filter looks to see if the file name contains an indication
+//!   of which libc it was compiled against. Typically, this is something like "-gnu" or "-musl". If
+//!   it does contain this indicator, names that are _not_ musl are filtered out. However, if there
+//!   is no libc indicator, the asset will still be included. You can use the
+//!   [`UbiBuilder::is_musl`] method to explicitly say that the platform is using musl. If this
+//!   isn't set, then it will try to detect if you are using musl by looking at the output of `ldd
+//!   /bin/ls`.
 //!
 //! At this point, any remaining assets should work on your platform. If there's more than one at
 //! this point, it attempts to pick the best one.
 //!
 //! - If it finds both 64-bit and 32-bit assets and you are on a 64-bit platform, it filters out the
 //!   32-bit assets.
-//! - If you've provided a `--matching` string, this is used as a filter at this point.
+//! - If you've provided a string to [`UbiBuilder::matching`], this is used as a filter at this
+//!   point.
 //! - If your platform is macOS on ARM64 and there are assets for both x86-64 and ARM64, it filters
 //!   out the non-ARM64 assets.
 //!